Incandescent light sources produce light using a filament wire which is heated by an electric current being driven through it until it glows. The filament is commonly housed within a glass or quartz bulb filled with inert gas or that is evacuated to protect the heated filament from oxidation and other processes that may be damaging. In a halogen luminaire, filament evaporation is further prevented by the usage of a chemical process for redepositing metal vapour onto the filament, whereby its lifetime is extended considerable. Hence, halogen luminaires are commonly used for lighting applications.
Light emitting diodes (LEDs) are currently among the most efficient light sources available today. Luminaries comprising LED light sources consume less energy than incandescent light sources. LEDs also have a longer lifespan than conventional light sources and need to be replaced less frequently, having the advantage that the light source may be integrated in the luminaire, without using sockets for easy replacement.
To provide LED luminaires that mimic the light emission distribution and appearance of incandescent light sources such as halogen luminaires is however problematic for a number of reasons.
US-2012/0262050 discloses a LED light with a housing comprising prisms which are arranged such that the visual effects of the LED lights is improved.
There is, however, a need to further improve the performance and appearance of LED luminaires that mimics the visual appearance and light emission of incandescent light sources such as clear halogen capsule lamps.